The present invention relates to a torque motor, and more particularly to a torque motor suitable for use in driving a throttle valve for automobiles.
A throttle valve control device for automobiles includes a controller, an actuator for driving a throttle valve, and a throttle valve. The throttle valve control device has employed a motor rotating over an angular range of 360.degree. as the actuator for driving the throttle valve. (U.S. Pat. No. 4,388,913).
However, the throttle valve for automobiles does not make a complete revolution; it rotates about 90.degree.. For this reason, rotation of the motor is converted to finite rotation of the throttle valve through a gear or the like.
Using such a motor which rotates 360.degree. has involved disadvantages, in that no current flows in some of the coils due to rectification, and torque is not always generated effectively, dependent on the form of winding wires. This results in the disadvantage that the motor is relatively large with respect to its torque.
Inherently, therefore, a motor for driving the throttle valve to rotate through an angular range corresponding to the opening thereof is sufficient; it need not rotate over 360.degree.. Nevertheless, the motors which rotate 360.degree. have been employed as the actuator for driving the throttle valve in the conventional throttle valve control device.